Method and Device for Compacting a Web of Endless Fabric Including a Nonwoven

ABSTRACT

A method and a device are for compacting a web of endless fabric including a nonwoven. According to the method and device, the web of endless fabric is subjected to the following treatment steps: a) impinging the web of endless fabric with a pressurized liquid; b) sucking off liquid; c) squeezing off liquid; and d) drying the web of endless fabric.

FIELD OF THE INVENTION

The present invention relates to a method and a device for compacting a web of endless fabric including a nonwoven.

BACKGROUND INFORMATION

It should be understood that a web of endless fabric including a nonwoven includes webs of endless fabric which consist completely of nonwoven.

A nonwoven is a sheet-like textile structure consisting of filaments which are bonded thermally, chemically or mechanically to one another.

Mechanical compacting includes the conventional method of water jet compacting, in which water jets are supplied under pressure to at least one surface of the nonwoven and cause a compacting of the nonwoven.

After the step of action by water jet, it is necessary to dry the nonwoven. For this purpose, it is conventional to supply the nonwoven subsequently to a suction device, by which water is sucked away, and finally to a dryer, in which the evaporation of residual liquid contained in the nonwoven is brought about.

Particularly the processing step of drying in the dryer is energy-intensive.

SUMMARY

Example embodiments of the present invention may provide a method and a device for compacting a web of endless fabric including a nonwoven, the energy requirement of which may be lowered.

In the method according to an example embodiment of the present invention, before the drying step, liquid is squeezed away from the web of endless fabric including already compacted nonwoven.

The liquid content of the web of endless fabric can be lowered by this measure, before drying, to an extent such a more favorable energy balance may be obtained, overall, as compared with conventional methods. This result may be considered surprising because that the quality of the nonwoven is not adversely influenced by the squeezing in spite of the mechanical action associated with this.

The step of squeezing away liquid may be employed instead of the suction extraction adopted hitherto. It may be provided, however, that, before squeezing, excess liquid is also sucked away, since the effectiveness of the squeezing-away operation is thereby increased and a web of endless fabric of lower residual moisture can be supplied to the drying operation. A particularly careful drying operation may be brought about by suction extraction prior to squeezing. This can be explained by lower transverse flows of the liquid during the squeezing-away step, since, because of the lower residual moisture, only smaller liquid quantities per unit time have to emerge from the nonwoven.

The liquid used may be water. Although it is possible also to employ other liquids, for example more volatile at room temperature, for compacting the nonwoven, the use of water continues to be preferred, since this is the most cost-effective and presents no problems of provision and/or disposal.

The device for applying the method includes an arrangement, by which liquid which is under pressure can be supplied to the web of endless fabric, a squeezing mechanism which follows the arrangement and by which liquid can be squeezed away from the web, and a dryer for drying the web of endless fabric. In this device, the web of endless fabric is supplied continuously from the compacting arrangement to the dryer via the squeezing mechanism, and, after running through the squeezing mechanism, the web of endless fabric has such a low residual moisture that the energy quantity required for causing the drying operation by the dryer is reduced.

So that the energy requirement can be lowered even further, it may be provided that the device additionally includes a sucker for sucking away excess liquid, which precedes the squeezing mechanism, as seen in the direction of advance of the web.

Example embodiments of a method and a device are explained in more detail below with reference to the appended FIGURE.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE illustrates an example embodiment of the present invention.

DETAILED DESCRIPTION

The device, designated as a whole by 100, includes a compacting arrangement 1. The latter has a drum 2, around which the web of endless fabric B including the nonwoven to be compacted is led over about 220°. Disposed so as to be distributed over a part circumference of the drum 2 are nozzles 3, by which water jets 4 can be supplied under pressure in the direction of the normal to the web of endless fabric B.

After running around the drum 2, the web of endless fabric B is guided by a traveling screen 8 revolving endlessly around deflection rollers 5, 6, 7 at the speed of advance of the web of endless fabric. In the region in which the web of endless fabric B bears against the traveling screen 8, a suction device 9 is provided on that side of the traveling screen 8 which is opposite the web of endless fabric B. The suction device includes a suction beam 10 which can be acted upon by a vacuum and which includes a suction-extraction port 11 extending over the entire width of the web. By the suction device 9, part of the liquid supplied to the web of endless fabric by the nozzles 3 is extracted from the web of endless fabric B.

The web of endless fabric B is supplied via further deflection rollers 12, 13 to a squeezing mechanism 14. The latter includes a pair of squeezing rollers 15, 16 which between them form a squeezing nip 17. The pressure force of the squeezing rollers 15, 16 on the web of endless fabric B led through the squeezing nip 17 is dimensioned such that a further part of the liquid which still remains in the web of endless fabric is squeezed away, but mechanical action on the web of endless fabric is not to an extent such that the quality of the web of endless fabric could be impaired.

Via two further deflection rollers 18, 19, the web of endless fabric B is supplied to a dryer 20 for extracting the residual moisture and is subsequently delivered for further treatment or winding-up.

LIST OF REFERENCE CHARACTERS

-   100 Device -   1 Compacting arrangement -   2 Drum -   3 Nozzles -   4 Water jets -   5, 6, 7 Deflection rollers -   8 Traveling screen -   9 Suction device -   10 Suction beam -   11 Suction-extraction port -   12, 13 Deflection rollers -   14 Squeezing mechanism -   15, 16 Squeezing rollers -   17 Squeezing nip -   18, 19 Deflection rollers -   20 Dryer -   B Web of endless fabric 

1-3. (canceled)
 4. A method for compacting a web of endless fabric including a nonwoven, comprising: acting upon the web of endless fabric by liquid under pressure; sucking away of liquid; squeezing away of liquid; and drying the web of endless fabric.
 5. The method according to claim 4, wherein the liquid includes water.
 6. The method according to claim 4, wherein the liquid consists of water.
 7. The method according to claim 4, wherein the sucking away of the liquid is performed subsequent to the acting upon the web of endless fabric by the liquid under pressure, the squeezing away of the liquid is performed subsequent to the sucking away of the liquid, and the drying of the web of endless fabric is performed subsequent to the squeezing away of the liquid.
 8. A device for compacting a web of endless fabric including a nonwoven, comprising: a compacting device adapted to supply liquid under pressure to the web of endless fabric; a squeeze mechanism downstream of the compacting device configured to squeeze away liquid from the web of endless fabric; a suction device upstream of the squeeze mechanism; and a dryer configured to dry the web of endless fabric.
 9. The device according to claim 8, wherein the device is configured to perform a method including: acting upon the web of endless fabric by the liquid under pressure; sucking away of liquid; squeezing away of liquid; and drying the web of endless fabric.
 10. The device according to claim 8, wherein the suction device is upstream of the squeeze mechanism and downstream of the compacting device.
 11. The device according to claim 8, wherein the dryer is downstream of the suction device.
 12. The device according to claim 8, wherein the dryer is downstream of the suction device.
 13. A device for compacting a web of endless fabric including a nonwoven, comprising: means for acting upon the web of endless fabric by liquid under pressure; means for sucking away of liquid; means for squeezing away of liquid; and means for drying the web of endless fabric.
 14. The device according to claim 13, wherein the means for sucking away of the liquid is located downstream of the means for acting upon the web of endless fabric by the liquid under pressure, the means for squeezing away of the liquid is located downstream of the means for sucking away of the liquid, and the means for drying the web of endless fabric is located downstream of the means for squeezing away of the liquid. 